The present disclosure relates generally to actuator assemblies, and more specifically, but not by limitation, to a vibration damper for an actuator assembly.
Actuator assemblies are utilized in many environments and include a positioning assembly (referred to as the “actuator”) that is movable within the actuator assembly for generating or controlling motion relative to a mechanism or system. For instance, actuator assemblies are frequently used to introduce motion, or prevent motion (e.g., clamping an object), within a system. Actuator assemblies can be utilized in applications where linear and/or non-linear movement is desired and can include, by way of example, electric, pneumatic, and hydraulic sources, to name a few. For instance, one example of an actuator assembly is an electric motor that uses electrical energy to produce mechanical energy through electromagnetic means. Examples of electric motors that utilize electromagnetic means to produce mechanical energy include stepper motors and voice coil motors, to name a few.
Actuator assemblies are frequently utilized in environments where precise movement is desired. For instance, in an exemplary data storage system environment an actuator assembly (e.g., a voice coil motor) includes a positioning assembly or actuator utilized to position a transducer over a media surface. In a voice coil motor, an electric current is applied to a coil of the positioning assembly. The current in the coil interacts with a magnetic field produced by a magnetic assembly (e.g., one or more permanent magnets) to produce a force on the coil thus moving the actuator assembly in a desired direction. In one example, the coil of the positioning assembly or actuator is positioned in a magnetic pole gap of the magnetic assembly and experiences a force proportional to the current passing through the coil.
In the data storage system example, during a seek operation the positioning assembly or actuator is rapidly moved to a target position on the media by sending a current through the coil of the actuator. Upon arriving at the target position, a large portion of the kinetic energy in the actuator excites mechanical vibrations of the actuator. For instance, forces associated with the deceleration of the actuator cause torsion and/or bending of the actuator, which can result in mechanical vibration and/or oscillation of the actuator. The particular vibration modes associated with the actuator can cause servo errors, some of which are typically known as “post-seek oscillation” or “seek settle” errors, and can result in failed seek operations and/or a decrease in desired or specified performance. For instance, vibration associated with the actuator can cause position error of a transducer attached to the actuator and can result in failed read and/or write operations of the transducer.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.